This invention relates generally to the manufacture of ophthalmic lenses and more particularly concerns conformal tools for fining and polishing ophthalmic lenses.
Most known finishing/polishing tools provide a global conformance to the lens, requiring a separate tool for every possible contour of lens. For each lens, the proper tool has to be selected and mounted on the fining/polishing apparatus. With recent development of more accurate lens surfacing equipment, modern lenses exhibit wide variations in face curvature.
While some work has been done in the development of conformal tools which can be used to fine/polish a variety of lenses, little success has been achieved in developing a single or minimal number of fining/polishing tools which will conform to all contours of lenses including toric lenses. For the most part, improved conformal tools are progressively incremented in diopter ranges so that the tool does not accurately conform progressively at any position of a lens contour. Thus, the fining/polishing process can adversely effect the accuracy of the lens geometry.
One presently known conformal tool applies air pressure under the control of the operator in the bladder of the conformal tool to control the degree of conformance to the lens. However, the use of air pressure or hydraulic pressure in the tool bladder under operator control introduces considerable inaccuracy into the system. In addition, the face of the tool tends to buckle and lose its integrity with the lens surface, introducing further error into the system.
Other recently developed conformal tools use a conformable filler in a pliant casing to contour the tool to the lens. Such tools eliminate the introduction of error due to the operator's subjective introduction of air into the bladder. However, all the fluids or particles of the conformable filler are free to shift in any direction in response to the many forces exerted on the tool including the rotational motion of the tool and the axial displacement of the tool as well as the contour of the lens. Consequently, not all fluid or particle movement is directed toward achieving conformance.
It is, therefore, an object of this invention to provide a conformal tool for fining/polishing ophthalmic lenses affording unidirectional movement of the conformal medium toward the lens. Another object of this invention is to provide a conformal tool for fining/polishing ophthalmic lenses which restricts movement of the conformal medium in any direction other than toward the lens. Still another object of this invention is to provide a conformal tool for fining/polishing ophthalmic lenses which transforms multidirectional pneumatic pressure into unidirectional mechanical force to achieve conformance of a diaphragm to a lens. It is also an object of this invention to provide a conformal tool for fining/polishing ophthalmic lenses which uses a diaphragm to transfer multidirectional pneumatic pressure to a cluster of rods unidirectionally arranged in slidable tangential contact with each other. A further object of this invention is to provide a conformal tool for fining/polishing ophthalmic lenses which is capable of fining and polishing any lens within the range of piano to 14 diopters. Another object of this invention is to provide a conformal tool for fining/polishing ophthalmic lenses which is capable of fining and polishing any lens within a range of piano to 14 diopters with at least the added capability of 4 diopters of cylinder. Yet another object of this invention is to provide a conformal tool for fining/polishing ophthalmic lenses which is usable for both fining and polishing.